SENSOR PRODUCTS APPLICATIONS Linear / Angular / Rotary Linear Displacement Displacement Sensors Angular Displacement HMC1501 / HMC1512 Motor Control Valve Position igh resolution, low power MR sensor capable of measuring the angle Proximity Detection H direction of a magnetic field from a Current Spike Detection magnet with <0.07 resolution. Advantages of measuring field direction versus field strength include: insensitivity to the tempco of the magnet, less sensitivity to shock and vibration, and the ability to withstand large variations in the gap between the sensor and magnet. These sensors may be operated on 3 volts Not actual size with bandwidth response of 0-5 MHz. Output is typical Wheatstone bridge. FEATURES AND BENEFITS No Rare Earth Magnets Unlike Hall effect devices which may require samarium cobalt or similar rare earth magnets, the HMC1501 and HMC1512 can function with Alnico or ceramic type magnets. Wide Angular Range HMC1501Angular range of 45 with <0.07 resolution. HMC1512Angular range of 90 with <0.05 resolution. Effective Linear Range Linear range of 8mm with two sensors mounted on two ends range may be increased through multiple sensor arrays operating together. Absolute Sensing Unlike incremental encoding devices, sensors know the exact position and require no indexing for proper positional output. Non-Contact Sensing No moving parts to wear out no dropped signals from worn tracks as in conventional contact based rotary sensors. Small Package Available in an 8-pin surface mount package with case dimensions (exclusive of pins), of 5mm x 4mm x 1.2mm total mounting envelope, with pins of less than 6mm square. Large Signal Output Full Scale output range of 120mV with 5V of power supply.HMC1501 / HMC1512 SENSOR PRODUCTS PRINCIPLES OF OPERATION Anisotropic magnetoresistance (AMR) occurs in ferrous Metal Contact materials. It is a change in resistance when a magnetic Current M field is applied in a thin strip of ferrous material. The mag- Flow 2 netoresistance is a function of cos where is the angle between magnetization M and current flow in the thin strip. Permalloy When an applied magnetic field is larger than 80 Oe, the Thin Film Applied magnetization aligns in the same direction of the applied (NiFe) Field field this is called saturation mode. In this mode, is the angle between the direction of applied field and the current Applied Field Direction flow the MR sensor is only sensitive to the direction of applied field. M M The sensor is in the form of a Wheatstone bridge (Figure 1). The resistance R of all four resistors is the same. The bridge R+ R power supply V causes current to flow through the resistors, R- R S the direction as indicated in the figure for each resistor. V I Both HMC1501 and HMC1512 are designed to be used in + - Vs saturation mode. HMC1501 contains one MR bridge and HMC1512 has two identical MR bridges, coexisting on a MM single die. Bridge B physically rotates 45 from bridge A. R+ R The HMC1501 has sensor output V=-V S sin (2) and R- R S the HMC1512 has sensor output V=V S sin (2) for sen- S sor A and sensor B output V =-V S cos (2), where V is S S S supply voltage, S is a constant, determined by materials. For Honeywell sensors, S is typically 12mV/V. Figure 1 PINOUT DRAWINGS HMC1501 HMC1512 OUT+ 1 8 OUT- OUT- A 1 8 GNDA GND 1 2 7 GND 2 OUT- B 2 7 GNDB 3 6 VBRIDGEB 3 6 OUT+ B 4 5 VBRIDGE VBRIDGEA 4 5 OUT+ A Caution: Do not connect GND or Power to Pin 3,4 &6. MR SENSOR CIRCUITS VBRIDGE VBRIDGE A OUT +B VBRIDGE B R R R R R R Bridge B R OUT+ OUT- OUT+ OUT- Bridge A A A R R R R R GND B OUT -B GND 1 GND 2 GND A 2